Javascript DHTML Drop Down Menu Powered by


(re safety differently ADQ6. a) & b)

(published 24/2/18).



6. On a related part of the HSW web site, a Professor of Construction Management says he too (i.e. as well as Dekker) utilises the Deepwater Horizon disaster “to highlight the errors in Heinrich/Bird triangles”. He continues, “Senior managers were on the oil platform assessing issues such as PPE and safe "behaviours", the base of the triangle, giving them a clean bill of health. A few hours later there was a catastrophic explosion, a top of the triangle event, with the two being unrelated”.   


Note: This is the 4th reference to Heinrich’s triangle and (including a reference in the piece on Dekker’s book) the second Professor to reference Deepwater Horizon.



a). What errors exist in the triangles produced by Heinrich and Bird?

b). Why are Professors in the 2nd decade of the 21st Century referencing matters put forward in 1929 as relevant to the Deepwater Horizon disaster?



Clear from other discussions (see here for instance), there are no errors in the triangles; indeed, given their purpose, it is not possible for them to contain any. Furthermore, and contrary once again to the Professor of construction management, the bases of the triangles represent near-misses, they are not concerned with ‘positive’ occurrences such as PPE use or safe behaviours. Consequently, some may need to re-visit the relevant texts since, 88 years on, disastrous blunders are still being made in respect of Heinrich’s most critical, yet basic and elemental, findings. 

As for ADQ6b generally, that was addressed here. As for the Deepwater Horizon references, argumentum ad passiones may be apt.




The Institute of Industrial Accident Investigators. All rights reserved.